Generally speaking, there are a variety of applications wherein a tubular member is utilized to convey fluids and/or prevent fluid intrusion. Thus, the tubular member might, by way of example, be utilized to maintain one or more fluids externally and/or internally thereof, e.g., in the case of a gas or liquid conveying or storing pipe or tank or in the case of an electrical conduit or the like where ground water intrusion must be prevented. For all such applications, it is usually critical that the integrity of the tubular member be maintained throughout its length.
In many instances, the tubular member is relatively small in diameter making any repairs difficult if not impossible. There are sewer pipes, for instance, that are on the order of approximately ten inches in diameter which means that any cracks, holes or other breaks, ruptures, tears or gaps must usually be repaired by replacing the pipe which is not only time consuming but very expensive as well. Moreover, with pipes of this diameter, it is usually difficult to pinpoint the exact location of leakage to facilitate repair.
Along these same lines is the fact that leakage in older pipes is often an indication of a general problem in the form of deterioration thereof. It would, nonetheless, be desirable to avoid the necessity of replacing the pipe, or awaiting an ever increasing frequency of leaks and repair, provided there was a suitable technique for substantially restoring or improving the structural integrity of the pipe for its intended purposes. However, in order to be feasible, it is essential that such a repair not only substantially extend the life of the pipe but also do so in a cost effective manner.
In the past, there have been a variety of techniques proposed for successfully addressing these problems. For instance, it has been proposed to adhesively impregnate felt material or the like and use an expansible member to press the material into contact with the inner wall thereof until the adhesive cures and bonds the felt to the pipe. Unfortunately, this technique has not been successful since the felt is subject to shrinkage and an annulus may typically form between the felt and the pipe.
As will be appreciated, the shrinkage of the felt as the adhesive cures means that any fluids which reach the annulus as at the juncture of two interconnecting pipes will still leak. It is also the case that the absence of any bonding of the felt liner to the inner wall of the pipe means that there will be no reinforcement or enhancement of the structural integrity of the pipe which may well be in a deteriorating condition particularly for applications involving pipes that are a part of the generally recognized deteriorating infrastructure of cities such as sewer pipes and the like. Moreover, since the felt liner expands to a fixed diameter, it can wrinkle if the inner diameter of the pipe is less than expected or tear if the inner diameter of the pipe is greater than expected.
While such an approach is of interest, it has remained to provide an entirely satisfactory liner adapted to be permanently adhesively affixed to an inner surface of any tubular member.
The present invention is directed to overcoming one or more of the problems and accomplishing one or more of the resulting objectives as aforementioned